The mercy of the tide
The ocean is a powerful force with its own rules and laws. An unexpected tide not only can interfere your rest, but also poses real adrenalin, both to humans and to those who are on board the yacht in the wrong place and at the wrong time!
Of course, each of us remembers from school books that the tide is a rise of the water level in the ocean, and even in 1687 Isaac Newton found out that this phenomenon was caused by the gravitational forces of the Moon, the Sun and the Earth. Therefore, for those who are going in a yacht trip, it is worth knowing some important features. For example, in coastal areas, there are two high tides and two low tides every 24 hours and 50 minutes, and their time and peak depend on wind and atmospheric pressure.
Navigation tides in marinas
Obviously, there is ebb and flow data for any location on the coast. Most of them include three main parameters: date, time and tide height. Also, such tables can contain information about the speed and direction of tidal currents, which are of decisive importance.
An important part of reading the tide table is determining the datum of the map. Simply put, it is the average of the ebb and flow. The tide charts indicate the depth of the water at a given time, and to get the average value of the tide heights, you need to take into account additional data from the tables. As a rule, you can find data on the lowest tides when they do not fall below this point.
All this information also helps to navigate when entering and exiting the marina. For example, you may be faced with a situation where the water begins to leave and the boat may bank on one side. Dangerous situations also arise when passing under power lines. If this is a sailing yacht, then you usually know the mast height, but it is also vital to have information about the height of the tide, how fast the water is arriving and when it will subside.
Well, the most common situation when the tide can unpleasantly affect yachting is low water at the entrance to the marina. The locks, which are used to equip the marina’s tidal zones, retain such an amount of water that the vessel can safely stand moored. Under these conditions, enter or exit the marina, for example, because of the risk of running aground or on bare reefs.
It is worth mentioning such a concept as a tidal wave. It arises along the coast, in estuaries and narrow bays where the river flows into the ocean. It is this “wave” that is responsible for the highest tides in the world, and this phenomenon can be observed in Canada.
Bay of Fundy is a natural wonder! You involuntarily feel this, walking along the bottom of the ocean, as soon as the water recedes! The tides in this coastal zone reach 16 meters – this is practically the height of a 5-storey building, and the water level here rises every hour by an average of eight meters. It is impossible to convey the full range of emotions when you are in a boat and you feel that the water around does not just come, it “grows”. Just a few hours ago, giant stones towered over the beach, but now they have already gone partially under the water and you can swim up to them and marvel at their natural grinding.
One more bay can be put on a par with Fundy – Ungava. It is located south of the Hudson Strait and is surrounded by small islands and bays. Despite the fact that the deepest part of the bay is only 150 meters, in the spring at the mouth of the River Lif the water rises by as much as 17 meters. The climate in this part is very harsh – from October to July Ungava is covered with ice. Polar bears and walruses can often be seen migrating from the Hudson Strait to the west coast of the Gulf on ice floes.
The Atlantic coast of France is another very high tide zone. On the border between Normandy and Brittany, there is the bay of Mont Saint-Michel, which at high tide turns almost entirely into an island. And the castle with the same name gives a sense of unreality of what is happening. Its fantastic silhouette rises above the water, giving the impression that the abbey is floating above the water.
The city of Saint-Malo in Bretagne has been living in the rhythm of the tides for centuries now, where the water drop is no less than 17 meters. The tides intensify during the full moon and new moon. The water actually resides here at the speed of a human step.
The tidal current, incredibly beautiful and powerful, can be seen in the north of Norway in the Saltstraumen Strait. This place beyond the Arctic Circle is well known to divers and fishermen. The water here rises by an average of 2.5-3 meters – not as much as in other parts of the world. But the uniqueness of this place is that the fjords are separated by islands, and the level differences between the sea form eddies of huge diameter – up to 12 meters.
It should be remembered that tides are a huge danger, especially if they were caught by surprise. But if you skillfully use the knowledge about them, you can enjoy an incredible sight.